An investigation into the Future of Hydroelectricity (Essay Sample)

An investigation into the Future of Hydroelectricity Name of Student Institution Affiliation Introduction Simply put, hydroelectricity is electricity derived from water. In a hydroelectric power plant, a reservoir stores potential energy in water at a point of high elevation. When this water is released it goes through turbines which in turn drive the generators that create electricity. Producing hydroelectric energy at scale requires a serious investment in infrastructure. The constructed dams often cover hundreds to thousands of square kilometers. Hydroelectricity is an important source of energy in the world. It is, in fact, the leading source of renewable energy. It makes up about 70% of the world’s total renewable energy sources (Zarfl et al., 2015). The aim of this essay is to investigate the contribution of hydroelectricity to the energy demands of the world. This investigation starts by looking at the advantages of power generation using hydroelectricity. The discussion then shifts to how hydroelectricity is produced at scale. Finally, the challenges and the future of hydroelectricity are debated. The advantaged of hydroelectricity Energy The popularity of hydroelectric energy is related to the advantages that it confers to society. The key advantage of hydroelectricity is that its production cost per Kilowatt-hour is low. In the United States, for example, a station that has an installed capacity of above 10 megawatts will on average produce electricity at the rate of three to five cents per kilowatt hour. This low cost makes hydroelectric energy viable for use in industries. This low cost is a result of two key factors. The first factor is the fact that storing water in a dam reservoir is a low-cost event (Bejarano et al., 2017). Furthermore, maintaining a hydroelectric power plant is not expensive. Most of the materials that are used in the construction are durable. Most of the hydropower plants are usually still fully functional fifty to a hundred years after they were commissioned. The different uses of Dams. Source: Federal Emergnecy Management Agency FEMA The other advantage of hydroelectricity is its flexibility. The amount of power generated from hydroelectricity can easily be varied depending on the demand from the grid. A hydro turbine can be started in a matter of seconds. The conventional approach to power production in hydropower plants is to use a limited number of turbines in power generation (Fearnside, 2015). The full capacity is used only when the demand is high or when the reservoir needs to be emptied due to flooding. This flexibility also extends to the infrastructure that forms the hydropower plant. The dam reservoir can, for example, be used for irrigation, fish farming, and water sport (Kaygusuz, 2016). The ability to use the dam for alternative functions stems from the fact that power generation does not use up the water that is stored in the dam. It merely harnesses the potential energy that is a result of the height of water. Combine this flexibility with the fact that hydroelectricity does not produce any waste and it is clear as to why it is popular. Generating Hydroelectric Energy in Scale As already noted, producing hydroelectricity is a capital intensive affair. This fact is further especially true when the hydroelectric power plant in question is a large one. Take the case of the largest dam in the world, the Three Gorges Dam. it has a total capacity of 22,500 megawatts (MW) (Pérez-Díaz et al., 2016). The dam covers a total area of 1,045 square kilometers and has a wall with a height of 181 meters (Fecarotta et al., 2015). Building this particular dam took a total of seventeen years. The conventional way to generate hydroelectric power requires the construction of a dam. This dam collects water from a source usually a river. Water from the dam flows down a large pipe called a penstock. The water from this pipe spins a turbine which is attached to a generator. The generator, in turn, produces electricity that is transmitted to the grid. The Largest Hydro Power Dam in the Word: Three Gorges Dam, South East China Hydroelectricity can also be produced using other techniques. One such technique is pumped storage. A hydropower plant that uses this technique will use the excess electricity that it generates to pump water from a low point to the highest point of the reservoir. When the demand for electricity peaks, the pumped water is then used to generate electricity (Hirth, 2016). The other unconventional method is the runoff river technique. In this case, the electricity is produced from a conventional river without the need of a reservoir. Already all these different techniques are being used to generate electricity at scale. Data British Hydropower Association indicates that hydroelectricity makes up 16.6% of the world’s total electricity (Gleick, 2015). Hydropower is the one source of electricity that is used in most countries of the world. Challenges with Hydroelectric Energy Hydroelectricity is not without its challenges. The amount of electricity that is produced through hydropower is dependent on the availability of water. In the years where the amount of rainfall is low, the electricity that is produced through hydropower decreases drastically. This variability is quite significant to the extent that some power plants only produce 10% of their normal capacity during this dry seasons (Engstrom, 2016). It is also not helpful that dams can be a major source of water wastage. Due to the availability of a large pool of water, dams are a major source of evaporation. A conventional dam can lose as much as 18,000 gallons of water during the hot months (Førsund, 2015). This wastage further contributes to the variability in the electricity that is produced. In such instances, countries that heavily depend on hydroelectricity are forced to generate electricity using fossil fuels. A Hydropower Dam with low Water levels due to Dry Weather Source: United Nations Environmental Department The other challenge with hydroelectricity is that it is damaging to the ecosystem. In a hydropower project, large tracts of land have to be dedicated to the construction of the dam. Land that was initially forest area is not spared. Both humans and animals alike have to be displaced to other locations. In the instances where a dam covers up forests and trees, it may lead to methane production (Eren, 2018). These degrading trees and plants decompose to produce methane which is a greenhouse gas (Fearnside, 2016). The standard practice today is to avoid this by clearing forest and vegetation as the dam construction continues. The most dreadful problem that can occur in a hydroelectric power station is dam failure. This is a situation where a poorly designed dam is damaged by extreme weather conditions. The result is usually loss of life and property. An example of such a disaster is the 1975 incident involving the Banqiao Dam in southern China (Cheng et al., 2015). A typhoon occurred in this region and the dam ended up carrying water beyond its ideal capacity. The result was the death of more than 26,000 individuals and a cholera epidemic that affected nearly 1,425 individuals (Cheng et al., 2015). Such incidences are however rare nowadays since stringent construction standards are now applied in dam construction. The Future of Hydroelectric Energy There is still a lot of potential to further expand the current hydroelectric infrastructure. This potential, however, varies from country to country. In developed countries, most of the rive resources have been exploited to the extent where there is little capacity to expand. Examples of this countries include Switzerland with a projected growth of 12% and Mexico with an expected growth of only 20% (Kern, Patino, & Characklis, 2014). Developing and third world countries, on the other hand, have a lot of potential for growth. Africa leads this park with a 95% potential for growth (Majone et al., 2016). Next is the middle east with the untapped potential amounting to 82%. Europe, North America, and South Africa have growth potentials of 71%, 75%, and 79% respectively (Prado et al., 2016; Sovacool, & Walter, 2018). It is unrealistic to expect all this potential to be tapped within a short period of time. The estimation is that by 2050, at least 25% of the available potential should have been achieved (Ansar, Flyvbjerg, Budzier, & Lunn, 2014). Projected Growth in Hydropower Generation in Different parts of the World: Developing and third world countries have the most Potential A major hindrance to the development of hydroelectric power is wind and solar energy. This two forms of renewable energy are increasingly preference over hydroelectricity. This is because both solar and wind have a higher potential compared to hydroelectricity. Additionally, the two can be tapped both on a small scale and on a large scale. Energy sources rivaling Hydropower; Source: EIA Projects United States This, however, does not mean that no hydroelectric projects are being conducted. There are over a dozen mega projects that are currently ongoing. The most significant of these is the Belo Monte Dam in Brazil, Tasang Dam in Buma with a potential to produce 35,446 GW annually, Xiangjiaba Dam in China, Siang Upper HE Project in India, and the Grand Ethiopian Renaissance Dam in Ethiopia (Melo et al., 2014; O'Connell, Collard, & Allcott, 2015). Most of this projects are however being plagued by conflicts on issues and water resources. Nonetheless, they will contribute to the expansion of hydroelectricity generation. Conclusion The investigation on hydroelectricity confirms that it is the major source of renewable energy on earth. This is because of years of investment into dams that generate hydroelectric energy. A hydropower dam consists of a reservoir, a turbine that is spun by the water in the reservoir, and a genera...